Find the following seven pieces of the diary that must be collected to unlock Night Omega in the corresponding locations:
World 1 (Elebit Forest) There is a hidden area at the top right corner of the map. Go to the bottom left corner of this area to find a crack with someone with the first piece of the diary. Elebits needed: Surf Omega, Ice/X Ice/Blizzard Omega, and Earth/X Earth/Land Omega.
World 2 (Elebit Mine) Deep inside the mine, at the upper left corner of the map, is a hidden area with a crack. Do not ride on the trail cart that will appear. Follow the tracks until you see someone with the second piece of the diary. Elebits needed: Flying Omega and Earth/X Earth/Land Omega.
World 3 (Resort Island) One of the village's residents has the third piece of the diary.
World 4 (Ice World) After retrieving the X Wind Omega, use this Elebit to turn the spinning wheels with arrows pointing to a direction. It leads to a resident in the middle of the area with the fourth piece of the diary.
World 5 (Ruined World) After subduing the second flowing volcano, there is a small hut on the upper right side of the map with the fifth piece of the diary.
World 6 (Sea Temple) The east side of the maiden's shrine, at the bottom left corner of the map, is an area where the sixth piece of the diary can be found. Elebits needed: Fly Omega, Radar Omega, and Earth/X Earth/Land Omega.
World 7 (Libra Of Crystal) After collecting the previous six pieces of the diary, the previously sealed golden door at the first floor of the upper left corner of the map will now be unlocked. It contains the final piece of the diary.